Electric motors are used in a wide variety of consumer and industrial products ranging from small, low-cost products to high-end products. Low cost products need an electronic motor controller that is inexpensive and requires only a small number of external components. High-end products, on the other hand, need more sophisticated motor control algorithms. The sophisticated motor control algorithms can be implemented by an upper control unit which provides commands to an integrated circuit (IC) motor controller. The upper control unit is typically implemented by a microcontroller (MCU) with on-chip memory containing software to direct the IC motor controller to perform precise motor speed and commutation actions.
In automotive environments, electric motors are used for several different applications including radiator fans, fuel pumps, water pumps, and oil pumps. In these environments it is important to provide several protection mechanisms to protect against fault conditions that could lead to safety hazards. However it has been especially difficult to design a single IC motor controller that is useful for most or all of these different applications.
The use of the same reference symbols in different drawings indicates similar or identical items. Unless otherwise noted, the word “coupled” and its associated verb forms include both direct connection and indirect electrical connection by means known in the art, and unless otherwise noted any description of direct connection implies alternate embodiments using suitable forms of indirect electrical connection as well.